Geochemical processes of formations of red-bed associated Cu-Co deposit at Kamoto, Zaire

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6196953

Hoy, L D; Ohmoto, H; Rose, A W

In the stratiform Cu-Co deposit at Kamoto, ore minerals occur in layers conformable to bedding, or as replacement of nodular and/or bedded dolomite within marine to littoral sediments overlying a thick continental red-bed sequence. delta/sup 13/C and delta/sup 13/O values of more than 70 dolomite samples from the red-bed, ore zone and unmineralized hangingwall sediments were determined to be -9 to +3 per thousand (PDB) and + 7 to +24 per thousand(SMOW), respectively. The delta/sup 13/C values correlate negatively with the amount of relict organic matter in the samples. Poor correlation between delta/sup 13/C and delta/sup 18/O indicates that dolomitization incorporating oxidized organic carbon occurred through a large temperature range. delta/sup 34/S values of about 70 ore sulfide samples range from -15 to +17 per thousand (CDT), correlating positively with both total S content of the samples and the delta/sup 13/C of associated dolomite. The isotopic data, the overgrowth and replacement textures observed among ore and gangue minerals, and the results of thermochemical calculations on the solubility and stability of the sulfides suggest that: (1) less than 30% of the sulfide sulfur in the deposit was fixed as bacteriogenic pyrite during early diagenesis; and (2) the Cu and Co sulfides were formed by later reaction between Cu-, Co- and SO/sub 4/-bearing hot (50-200/sup 0/C.) brines and the diagenetic pyrite, augmented by additional sulfate reduction through organic matter oxidation.

• Research Organization: Pennsylvania State Univ., University Park (USA)
• OSTI ID: 6196953
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580300* -- Mineralogy
Petrology
& Rock Mechanics-- (-1989)
580400 -- Geochemistry-- (-1989)
AFRICA
CARBON 13
CARBON ISOTOPES
CARBONATE ROCKS
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMISTRY
COBALT ORES
COPPER ORES
DEVELOPING COUNTRIES
DIAGENESIS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
GEOCHEMISTRY
GEOLOGY
HYDROTHERMAL ALTERATION
HYDROTHERMAL SYNTHESIS
IRON COMPOUNDS
IRON SULFIDES
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
MINERALIZATION
MINERALOGY
MINERALS
NUCLEI
ORES
OXYGEN 18
OXYGEN ISOTOPES
PETROGENESIS
PETROLOGY
PYRITE
QUANTITATIVE CHEMICAL ANALYSIS
ROCKS
SEDIMENTARY ROCKS
STABLE ISOTOPES
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SULFUR CONTENT
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
ZAIRE REPUBLIC